1. Field of the Invention
This invention relates to a rolling-contact bearing assembly, and, in particular, to a dust-free rolling contact bearing assembly for linear motion, which is so structured to prevent any undesired foreign material from getting into the assembly.
2. Description of the Prior Art
A linear motion rolling-contact bearing assembly is well known in the art. The linear motion rolling contact bearing assembly includes an elongated track rail, a moving table which is movable along the track rail and a plurality of rolling members interposed between the track rail and the moving table. The track rail is typically provided with outer guide grooves and the moving table is also provided with inner guide grooves and the rolling members are provided to roll along a guide passage defined by these inner and outer guide grooves. In such a linear motion rolling contact bearing assembly, since the track rail is substantially long as compared with the moving table so that the outer guide grooves of the track rail are normally exposed, which is sometimes disadvantageous because undesired foreign materials, such as debris and dust, may come to be deposited onto the outer guide grooves, which then could cause malfunctioning of the bearing assembly.